Method of making paper cups.



G. J. BOHLMAN.

METHOD OF MAKING PAPER CUPS.

APPLICATION FILED ms. 19.1915.

1,181,965. Pateiited May 2,1916.

l I I 1 if a v Wilt/less; M 7

1% @WM yww To all whom it may concern:

UNITED STATESLPATENT OFFICE.

GEORGE J. BOHLMAN, MEDFORD, MASSACHUSETTS.

METHOD OF MAKING PAPER CUPS.

Specification of Letters Patent.

Patented May '2, 1916.

Original application filed November 2, 1914, Serial No. 869,762. Divided and this application filed February 19, 1915. Serial No. 9,260.

Be it known that I, GEORGE J. BOHIlMAN, a citizen of the United States, residing at Medford, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Methods of Making Paper Cups, of which the following is a specification.

In another application 7 Serial No. 869,762, filed November 2, 1914, of which this application is a division, a paper drinking cup is shown having an improved form of rolled-edge at either or both ends of its body, A rolled-edge at the top of the cup is of advantage as contrasted with the usual thin sharp edge, as it gives additional stiffness and rigidity to the cup, and also presents a smooth lip-engaging portion which will not'have a tendency to cut the lip and a rolled-edge at the bottom of the cup is also of advantage, as by it a stiff flange is produced below the bottom-piece, by which to support the cup in upright position, even when filled, and by which the bottom-piece is held from dropping out, so that bottompieces composed of flat disks may be employed.

Heretofore, paper cups have been pro duced having rolled edges, but, so far as I am aware, the methods employed for producing the same has involved the employment of paraffin wax or some stiffening substance, which is applied to the surface of the cup-body, and which collects and hardens in the roll which is formed, thereby stiffening the edge to hold it in rolled position. In making the cup of said application in a manner involving My present method, I select a rather heavy 'stifi paper as comparedwith the paper usually employed for making drinking-cups. which paper contains a size or equlvalen stiffening substance by which itis also re at least partially wate roof, and cut from it a blank, and arrange the blank on a form thereby to produce a fr 1sto-c0nical or other shaped cup-body, andgt hen apply thereto, in any suitable mannen any suitable form of bottom-closure, although said bottomclosure may be applied at any other time,

cred waterproof or so far as the present process is concerned.

Then the end-portion of said cup-body is heated to a high temperature and 1s bent toform a roll andothenothe cup-bodv. sal

lowed to cool, whereupon the roll thus formed, becomes permanently set.

One Way of carrying out my invention is here shown which consists in holding the cup-body stationary, with that end-portion which is to be rolled in engagement with a rapidly-revolving heating and bending device, thereby heating the same by its frictional engagement therewith, and Whenheated or while it is being heated, applying pressure in a longitudinaldirection upon it, such for instance as the pressure of the hand, which is sufficient to cause its end-portion to follow the curvature of the heating and bending device, thereby to form the roll, and then removing the cup-body from the heating and bending-device and permitting it to cool, whereupon the rolled edge becomes permanently set. The apparatus inend-portion being rolled inward. The out-' wardly rolled edge is slightly stretched while it is being bent, which stretching isv permitted while the paper is at a high temperature, probably on account of the sof' tening of the sizing which is contained in the paper. On account of the paper which I prefer to employ in forming the cup,

being substantially waterproof, further wa' terproofing need not be resorted to, but if desired, the cup may be coated with paraffin wax in any well-known manner. The cupbody including its rolled edge is resilient, which. admits of its being withdrawn from a holder.

The method herein involved may be practised on other paper and other forms of receptacles as for instance, a cup-body may be made of paper in a well-known manner, and then coated with paraifin wax to render it waterproof, and then allowedto cool, ahd then the waterproofed cup-body may beheated or at least its end-portion, and while heated, its edge may be rolled, and subsequently allowed to cool, whereupon it becomes permanently set.

Figure 1, is a side elevation and partial vertical section of a paper cup, having its upper end rolled outward. Fig. 2, is a similar view of a paper cup. having its upper and lower ends rolled. one outward. and the other inri'ard. Pg. 3. is a detail view of a healing and bending device which may be employed in rolling the end-portions of the cupdaod). and Fig. l. is a similar view illustrating one endportion of the cup-body with its end-portion rolled.

Referring to Fig. l. 1 represents the cupbod) here shown as frusto-conical. and '2 the bottom-closure arranged in and adapted to close one end thereof. In this form of cup. the upper edge is rolled outward.

Referring to Fig. :2, 1 represents the cuphodv here shown as l'rusto-conical. and 3 the bottom-closure, which is represented as a disk. and in this form ol cup both ends of the cupbody are formed with rolled edges. the upper edge being rolled outward and the lower edge being rolled inward. the rolled edge at the bottom serving to hold the bottom-piece in place. or at leastfrom falling out.

Referring to Fig. 3, 19, represents a circular-member having a centrally disposed projecting portion 12 of frusto-conical form, and having a groove 13 arranged on the top of said member at the base of said projectingportion. Said member is arranged on a spindle 15 hearing a helt-pul ley 16. over which belt 17 passes. hv which to rapidly revolve said member. Said member constitutes the heating and bending-do vice for heating and bending one end. of the cup-body, and it will be understood that the other end of the cup-body will or may be bent or rolledin a similar manner. The dimensions of the frusto-conical projectingportion 12, are materially less than the corresponding dimensions of the cup-body. except at the base. which latter corresponds with the diameter of the cup-body. and a loose fit is thereby obtained, yet said projecting-portion will amply support the cupbody when the latter is placed thereon, proriding it is held h v he fingers or other means. and also will serve as a guide to dimet downward movement oi? the cup hodv when placed thereon. and Pl'kr r; i downward or longitudinal direction plied to it. sa v for instance. the pres. the hand. so

To roll the edge. the cizp io placed. on the rapidl revolving narniow. and its edge to be rolled cansml to enter the groove 1 and thus friction-ally engage the member 10. and while the cup-hotly is held stationary and the member l is revoh mg. said end-portion. which is in en; igement therewith. heated to a high temperature. care being taken notl'o scorch the paper. and while thus heated. pressure is applied 6 to the cnp-hodwin a downward or longitudinal direction. and said heated endpou tion is caused to follow the curved all of the groove 13. being expanded or stretc nai and rolled as represented in Fig. a 'l. cup-body is then removed from the heat?! and bending-device, and is allowed to whereupon its rolled edge becomes 5 nentlv set. The roll may be former: a.- complete circle as shown in Fig. l. but removing the cup-body from the heat and hemling-device before the roll has been thus formed. the roll will comprise a por tion only of a circle.

I claim n The method herein described of forming a rolled edge on the end-portion of a paper cup-body, "which consists in heating the endportion of the cup-body to a high ten-plj-=-.\ ture, and bending and snnnltant nsir stretching said end-portion while so heated. to form an outwardly extended roll. -nd then allowing the cupbodv to cool. whereupon the roll becomes permanently set.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses. I

GEORGE J. BOIILUA \Yitnt sses:

LIATlU-IRINl-I G. )lehnuua. Amos 1i. Tavron. 

